Abstract

The high demand of lithium for electromobility and energy storage requires an efficient and sustainable opti-mization of the current extraction from natural lithium brine process. In this context, this study develops a simultaneous Mg2+ and B3+ extraction system, which could be a contribution to the elimination of precipitation stages and the generation of high purity lithium brine. This dual system composed of a dialkylphosphate ionic liquid and a 2-ethylhexanol/kerosene mixture as magnesium and boron extractors, respectively, was optimized by a mathematical and statistical method known as response surface methodology (RSM). The RSM method identified, through a small number of experiments, the interdependencies of the parameters involved in the extraction process, and calculated their optimal values to achieve the maximum extraction efficiency of Mg2+ and B3+. The optimization was performed from two approaches. The first, maximizing the extraction of Mg2+ and B3+, resulted in experimental efficiencies of 99.17% of Mg2+, 99.36% of B3+ and 23.54% of Li+; whereas the second, in which lithium co-extraction was minimized, yielded efficiencies of 83.56% Mg2+, 99.22% B3+ and 3.36% Li+, results that demonstrate the high extraction capacity of the system, as well as proving the validity of the statistical model.